Accuracy of a semi?
- Thread starter deadman
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Well I guess I need to just get out and see what I can do. Not interested in buying a new receiver set to swap parts onto, I've done that before.
Modern Sporter with all SP1 parts except trigger, I put a TT in it. OG barrel, no idea what year it is or how many rds through it.
Bipod and squeeze bag, with Match Pro thrown on the vortex cantilever mount. Will see what I can do with both 55 gr fmj and 69gr smk.
It is what it is. Criticism welcome. Beauty ain't she?
Modern Sporter with all SP1 parts except trigger, I put a TT in it. OG barrel, no idea what year it is or how many rds through it.
Bipod and squeeze bag, with Match Pro thrown on the vortex cantilever mount. Will see what I can do with both 55 gr fmj and 69gr smk.
It is what it is. Criticism welcome. Beauty ain't she?
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Put a heavy march barrel on it if you can!
Beauty rifle for sure! Try a few groups using your bipod and a few rested on bags back by the magwell. The non-free-floated handguard will probably shoot to a different poi from the bipod compared to without. Not sure if 1:12tw will stabilise 69s, I'm pretty sure it won't stabilise 75s. Shoot a few rounds of 69s and see if they go through the paper cleanly.
That 12 twist will not stabilize the 69 smk. I wouldn't waste time or the bullets to try and see what they will do, but ymmv.
You might get something like a 60 - 62 grain amax to stabilize, but ss109s won't.
The best bullets will be in the 45 - 55 grain range.
You might get something like a 60 - 62 grain amax to stabilize, but ss109s won't.
The best bullets will be in the 45 - 55 grain range.
Accuracy of semi auto is only meaningful if the rate of fire is defined, and 10 round group is the minimum. Also - the percentage of arounds within the 10 round groups that are within a certain area. The distribution number and pattern count.
Back then when I still shot SVC ( and before skill fade ), I tested all my uppers with readily factory commercially available ammo loaded with SS109 balls (AE, PMC, IMI ).
My testing method was basically 300m monopod on a carpet ( what it is available at my range) and fire 10 shots at no slower than regular rate aka 10 rounds in 1 minute - I usually do this 2 or 3 times. I usually spray painted a 6" white circle on a piece of cardboard, and used mostly 4X sight like ACOG or Elcan DR.
The only uppers that capable of putting 80% shots in a 4.5" circle and mostly within a 6" circles are Colt canada free floated uppers like L119A2 Danish overrun and MRR, as well as all things made by HK ( MR, 416, doesn't mater if it is 11, 14.5 or 16, chromelined or not) - all CHF chromelined bbl by GFH machines with at least 0.85" dia. Giessele IURG with DD CHF bbl was able to do that in the first outtng but I did not have enough outings to finish before the OIC. And the most important - they are consistent. All HK guns absolutely RIP in accuracy with AE M855 balls. Multiple samples of different barrel lengths. FN CHF barrel is kinda behind HK and CC, the ones they sent to Noveske were phenomenal, but the one sent to BCM somehow were not as good, even though they claim to be the same.
A truly accurate semi ( or Semi system )can shoot reasonable good groups at high volume for a long time - and they are consistent across the board from the same factory. Bren 2 B&T APC G36..etc none can do what Colt Canada and Heckler and Koch could do. I have seen SP1 that did amazing single groups with old M193 balls - but can it repeat the same after 20, 30 or 50 rounds?
Back then when I still shot SVC ( and before skill fade ), I tested all my uppers with readily factory commercially available ammo loaded with SS109 balls (AE, PMC, IMI ).
My testing method was basically 300m monopod on a carpet ( what it is available at my range) and fire 10 shots at no slower than regular rate aka 10 rounds in 1 minute - I usually do this 2 or 3 times. I usually spray painted a 6" white circle on a piece of cardboard, and used mostly 4X sight like ACOG or Elcan DR.
The only uppers that capable of putting 80% shots in a 4.5" circle and mostly within a 6" circles are Colt canada free floated uppers like L119A2 Danish overrun and MRR, as well as all things made by HK ( MR, 416, doesn't mater if it is 11, 14.5 or 16, chromelined or not) - all CHF chromelined bbl by GFH machines with at least 0.85" dia. Giessele IURG with DD CHF bbl was able to do that in the first outtng but I did not have enough outings to finish before the OIC. And the most important - they are consistent. All HK guns absolutely RIP in accuracy with AE M855 balls. Multiple samples of different barrel lengths. FN CHF barrel is kinda behind HK and CC, the ones they sent to Noveske were phenomenal, but the one sent to BCM somehow were not as good, even though they claim to be the same.
A truly accurate semi ( or Semi system )can shoot reasonable good groups at high volume for a long time - and they are consistent across the board from the same factory. Bren 2 B&T APC G36..etc none can do what Colt Canada and Heckler and Koch could do. I have seen SP1 that did amazing single groups with old M193 balls - but can it repeat the same after 20, 30 or 50 rounds?
Agree on 10 rnd groups for semis. Also need to differenciate between ball ammo and match ammo. Your rifles that will do a consistent 2 moa or less with SS109/M855 (which is kinda crappy ammo, precision-wise) mono-podded using a 4x will most likely eke out more precision with mk262 or similar, a bipod and rear bag and a higher mag optic. A gas gun that shoots a consistent 2 moa with SS109/M855 is very solid. I'd expect the same rifles to shoot 1.5 moa or slighly better with match ammo like mk262 or similar. These claims of consistent sub-moa Canadian AR-180s are most likely cherry-picked 3 rnd groups or pure fantasy, imo.
I got about 2MOA with M193 and irons with an SP1 upper and NEA lower back when my eyes were way better, and frankly, that felt like a laser beam. I replaced it with a Norinco A1 clone upper because it shot exactly the same, and sold the SP1 to someone who'd appreciate it. I just wanted a shooter.
This is a 10-round group from my stock X95 and M193, which is pretty comparable with any AR I've shot with the same ammo. It was for the 1MADL challenge so it was a first attempt. I'm generally too cheap for match ammo and cant be bothered to re-zero for a handful of rounds but when I tried some 77gr XTAC it gave me 1.5" 5-round groups which I was quite pleased with.
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Precision also has context. It should be based on the ammunition that is abundant in supply - or easily obtainable, or commonly used.
A competitor or hunter who uses match or hunting ammo, the performance of mass produced ammo is not as relevant. Vice versa, a regular recreational shooter or lower level competition may find the performance of mass produced ammo more relevant.
Precision demand or expectation, therefore should be built on use case, but most importantly, the ammo to use.
A competitor or hunter who uses match or hunting ammo, the performance of mass produced ammo is not as relevant. Vice versa, a regular recreational shooter or lower level competition may find the performance of mass produced ammo more relevant.
Precision demand or expectation, therefore should be built on use case, but most importantly, the ammo to use.
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It takes a lot of work and handloads to get a M305 shooting 1.5 moa (without installing a match pipe). There was (is?) a long thread in the battle rifle section that is the 1.5 moa challenge. If I recall you needed to shoot 5x 5 rnd groups <1.5 moa. I could never quite make it, one group would always be just over although the average was generally <1.5 moa. That was in a M305 bedded into a modded fibreglass stock with all the NM mods done to it shooting handloads. Fun challenge for sure.
69 gr match kings are what I use in my 1:8 barreled M40a5 (ish) rifle.
They perform well in that rifle, but as posted by another member, the 1:12 isn't really suited for that. Doesn't hurt to try I guess, I've wasted more ammo than that in the past.
Hopefully get a chance to pick up a few different kinds this weekend when I'm home.
They perform well in that rifle, but as posted by another member, the 1:12 isn't really suited for that. Doesn't hurt to try I guess, I've wasted more ammo than that in the past.
Hopefully get a chance to pick up a few different kinds this weekend when I'm home.
Jard 180, 1.1 moa at 100m
Total all rounds 1.5 moa
IBI 18.6 stainless barrel,
Mid - grade trigger,
Leupold Mk 5 3-18x,
bipod and bag,
M855 62 grain ammo,
10 groups of 5 rounds each, slow fire and cooling between groups, average of 1.1 moa with an SD of .2 moa.
3 round called fliers and additional rounds fired to make each group full 5 rounds each.
1.5 moa when all rounds (50 total) combined (overlaid onto a single group).
Note; While 100m precision is interesting, remember that MV extreme spread (ES) is a geater determining factor for hit percentage at range.
i.e. at 600m a small ES will give you more hits than a small group.
This post aligns with my own, more limited, data;
** Tech Tuesday **
Today's message is for long-range shooters who might feel frustrated by inconsistent group sizes at 100 yards. While we all aim for the best possible groups, it’s important to be realistic about how much this truly matters compared to other factors. The reality is, we have limited time and resources, so it’s wise to consider the trade-offs when deciding which variables to focus on. In this case, we're comparing precision with muzzle velocity standard deviation (MV SD) for a load intended for long-range shooting.
Imagine you’re developing loads for your rifle and have one that produces tight groups at 100 yards but shows poor MV SD, versus another that gives average groups but has excellent SD. At 100 yards, one load clearly performs better, but what about at long range, where you actually intend to use the rifle?
Counterintuitive as it may seem, for long-range work, it's better to choose the load that produces larger groups at 100 yards but has a significantly lower MV SD. The reason is that MV SD leads to considerable vertical dispersion at long distances, far outweighing the short-range advantage of smaller group sizes.
Ultimately, consider your objective and prioritize the variables that will be most important in achieving it. While some factors are obvious, there are subtle trade-offs that may defy initial expectations. These unexpected realities, however, are just as important.
Follow for more long range shooting tips and visit https://thescienceofaccuracy.com/ to learn more!
#AppliedBallistics #TheScienceOfAccuracy #ballistics #longrangeshooting
Total all rounds 1.5 moa
IBI 18.6 stainless barrel,
Mid - grade trigger,
Leupold Mk 5 3-18x,
bipod and bag,
M855 62 grain ammo,
10 groups of 5 rounds each, slow fire and cooling between groups, average of 1.1 moa with an SD of .2 moa.
3 round called fliers and additional rounds fired to make each group full 5 rounds each.
1.5 moa when all rounds (50 total) combined (overlaid onto a single group).
Note; While 100m precision is interesting, remember that MV extreme spread (ES) is a geater determining factor for hit percentage at range.
i.e. at 600m a small ES will give you more hits than a small group.
This post aligns with my own, more limited, data;
Applied Ballistics
** Tech Tuesday **
Today's message is for long-range shooters who might feel frustrated by inconsistent group sizes at 100 yards. While we all aim for the best possible groups, it’s important to be realistic about how much this truly matters compared to other factors. The reality is, we have limited time and resources, so it’s wise to consider the trade-offs when deciding which variables to focus on. In this case, we're comparing precision with muzzle velocity standard deviation (MV SD) for a load intended for long-range shooting.
Imagine you’re developing loads for your rifle and have one that produces tight groups at 100 yards but shows poor MV SD, versus another that gives average groups but has excellent SD. At 100 yards, one load clearly performs better, but what about at long range, where you actually intend to use the rifle?
Counterintuitive as it may seem, for long-range work, it's better to choose the load that produces larger groups at 100 yards but has a significantly lower MV SD. The reason is that MV SD leads to considerable vertical dispersion at long distances, far outweighing the short-range advantage of smaller group sizes.
Ultimately, consider your objective and prioritize the variables that will be most important in achieving it. While some factors are obvious, there are subtle trade-offs that may defy initial expectations. These unexpected realities, however, are just as important.
Follow for more long range shooting tips and visit https://thescienceofaccuracy.com/ to learn more!
#AppliedBallistics #TheScienceOfAccuracy #ballistics #longrangeshooting
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An accurized Semi auto is capable of sub .5 moa from the bench. 5 round groups at 100 yards. Most of my AR10 rifles accomplished this with ease. Some of my AR15s as well. All had target triggers and precision barrels. Unfortunately they have been political prisoners for years now.
Currently the HK SL8 is your best bet. Not sure if any of the 308 rifles not banned are capable of this.
I will say that I disagree with the 10 round group theory. If the rifle has a semi heavy/varmint barrel and shots 5 rounds under .5 moa at 100 then it’s very accurate. If it’s a hunting rifle like a TC icon 308 and it shoots 3 rounds in the same hole before opening up. Then it’s a very accurate rifle.
The reason for this is testing the rifles accuracy vs heat dissipation of the barrel. A cold barrel is an accurate barrel. An M24 sniper rifle has an #8 barrel contour. You’re getting into sewer pipe barrels if you want those 10 round + consistent groups. While the 5R with a recontoured varmint profile from the same barrel will open up the groups faster as it heats up a lot faster. However the barrel and gun aren’t any less accurate. The barrel just heats up faster.
Anyways. All god fun. It will be a great day when our political prohibs get freed.
Currently the HK SL8 is your best bet. Not sure if any of the 308 rifles not banned are capable of this.
I will say that I disagree with the 10 round group theory. If the rifle has a semi heavy/varmint barrel and shots 5 rounds under .5 moa at 100 then it’s very accurate. If it’s a hunting rifle like a TC icon 308 and it shoots 3 rounds in the same hole before opening up. Then it’s a very accurate rifle.
The reason for this is testing the rifles accuracy vs heat dissipation of the barrel. A cold barrel is an accurate barrel. An M24 sniper rifle has an #8 barrel contour. You’re getting into sewer pipe barrels if you want those 10 round + consistent groups. While the 5R with a recontoured varmint profile from the same barrel will open up the groups faster as it heats up a lot faster. However the barrel and gun aren’t any less accurate. The barrel just heats up faster.
Anyways. All god fun. It will be a great day when our political prohibs get freed.
